A pioneering call for a new understanding of scale across the humanitiesHow is it possible that you are-simultaneously-cells, atoms, a body, quarks, a component in an ecological network, a moment in the thermodynamic dispersal of the sun, and an element in the gravitational whirl of galaxies? In this way, we routinely transform reality into things already outside of direct human experience, things we hardly comprehend even as we speak of DNA, climate effects, toxic molecules, and viruses. How do we find ourselves with these disorienting layers of scale? Enter Scale Theory, which provides a foundational theory of scale that explains how scale works, the parameters of scalar thinking, and how scale refigures reality-that teaches us how to think in terms of scale, no matter where our interests may lie. Joshua DiCaglio takes us on a fascinating journey through six thought experiments that provide clarifying yet provocative definitions for scale and new ways of thinking about classic concepts ranging from unity to identity. Because our worldviews and philosophies are largely built on nonscalar experience, he then takes us slowly through the ways scale challenges and reconfigures objects, subjects, and relations. Scale Theory is, in a sense, nondisciplinary-weaving together a dizzying array of sciences (from nanoscience to ecology) with discussions from the humanities (from philosophy to rhetoric). In the process, a curious pattern emerges: attempts to face the significance of scale inevitably enter terrain closer to mysticism than science. Rather than dismiss this connection, DiCaglio examines the reasons for it, redefining mysticism in terms of scale and integrating contemplative philosophies into the discussion. The result is a powerful account of the implications and challenges of scale, attuned to the way scale transforms both reality and ourselves.